There follows an explanation of what is meant by the term “selective decoupling of solidborne noise”.
Firstly concerning the concept of noise, it will be understood that the invention applies to the field of physical vibration and more particularly the range of audible sound.
Nevertheless, the term “noise” should be understood herein broadly, i.e. sometimes going beyond the spectrum of frequencies that can be perceived by the human ear, in other words the audible spectrum. In this respect mention is sometimes made of “high” frequencies.
Nevertheless, other ranges of vibration are sometimes also handled by the invention, on both sides of the audible spectrum. For example, the invention relates not only to ultrasound frequencies that can sometimes be troublesome (in particular for certain animals), but also to infrasound frequencies that contributes to the sound footprint of the aircraft.
The invention relates to the solidborne transfer of vibration. Two propagation paths for noise, e.g. in an aircraft, are commonly distinguished:                firstly the path whereby noise is radiated via various walls of the aircraft, with this noise path being known as “airborne” noise; and        secondly noise can be transmitted from vibrating material to vibrating material, which means that each component that is vibrating constitutes an additional source of noise: this noise is referred to as “solidborne” noise.        
Finally, there follows an explanation of the concept of decoupling. The decoupling to which the present application applies seeks to reduce the transfer of solidborne vibration. By analogy, it is somewhat similar to what happens in a lowpass filter.